Means for guiding aeroplanes on the ground



L. B. SPERRY MEANS FOR GUIDING AEROPLANES ON THE GROUND Feb. 16,1926..1,573,100

vFiled June 8, 1922 `329131 l Homo/13 7W .Parental Fea-1e, 192s. y

UNIT-ED STATES PATENT oFFlcE.

LAWRENCE B. SPERRY, F FARMINGDALE, NEW YORK; THE BANK 0F AMERICA, OF

NEW YORK, N. Y., AND WINIFRED ALLEN SPERRY, OF HEMPSTEAD, NEW YORK,EXECUTORS OF SAID LAWRENCEB. SPERRY, DECEASED. I

MEANS ECB GUIDING- AEROPLANES 0N THE GROUND.

Application filed .Tune 8, 1922. Serial No. 566,702.

To all 'whom zt may concern: v

Be it known that I, LAWRENCE B. SPERRY, a citizen of the United Statesof America, residing at Farmingdale, L. I., in the county of Nassau andState of New York, have invented certain new and useful Improvements inMeans for Guiding Aeroplanes ou 'the Ground, of which the following is aspecification.

particularly to means for controlling an aeroplane on the ground,especially when landing. i When an aeroplane is in flight and, of coursemoving rapidly, itsd direction of travel is controlled by themanipulation of plane surfaces which are acted upon by the strongrelative movement of theair. When landing, however, after the craft hasreached the ground and its speed becomes greatly rei duced, the controlplanes become ineffective for steering. This, however, is not ordinarilyof great importance, as it is customary when landing to head the craftdirectly intothe wind. This aids in bringing the craft to a quick stopand also obviates the necessity of steering it toward the end of itsmovements as there are practically no forces tending to divert the craftfrom a straight course and as the landing eld is large enough to permitthe craft to wander.

A very different problem is presented, however, when landing is to beveffected in a restricted place, as for instance, Aon a street or othernarrow piece of smooth ground. Under such'conditions, the aviator is`re'- stricted in the direction in which he mayliead his machine andcannot choose his landing direction in accordance with thc-l directionof the wind. Consequently, if the wind is blowing at an angle to theaircraft when a landing is made, there is no way of keeping the craft onits narrow path after it'has sloweddown to the point where the steeringplane or rudder becomes ineffective, and the craft is free to travel orto be blown whereit will.

The main object of theA present invention 5 may be steered when on theground, irre- This' invention relates to aeroplanes, and,

is to provide means whereby an aeroplane the craft when the length ofthe landing I space is also restricted.

vReferring to the drawings wherein I have shown what I now consider tobe the preferred form of my invention:

Fig. 1 is a perspective diagrammatic view of the control elements of anareoplane.

Fig. 2 is a side view of an aeroplane wheel with means for'braking thesame.

Fig. 3 is a plan view of the wheels with a modified means for actuatingthe brakes thereof.

Fig. 4 is a detail of one form of another form of brake actuating orsteering means.

In the drawings the aeroplane fuselage is indicated in dotted lines 1 inFig. 3, having the usual cockpit 2, within which is the aviators seat 3.Secured to the fuselage in the usual manner, notshown here, are thesupports 4 which carry the axle 5 which in turn carries the aeroplanewheels 6, 7.

In Fig. 1 the fuselage as well as the sus taining planes are omitted sothat the .control elements may be more clearly portrayed. The usualailerons are shown at 8, 9; the elevating control planes or hori- Zontalrudders at 10, 11, and the vertical or 'steering rudder at 12. Saidsteering rudder may be mounted on an upright post 13. The lower end ofthis post may constitute the usual tail skid4| and in this instance isshown as provided with a wheel 14. Near the forward end of the aircraftI have shown a control stick 15 pivotallyvattached at 16 to a bar 17.Said bar may in turn be mounted in bearings 18, 19, for rotation aboutits longitudinal axis but restricted against axial movement. Cords orwires 20, 21 may be connected at 22 to the stick 15- above4 its pivotalpoint 16 and to the lower ends of cross levers 23, 24 of elevatingplanes 10, 11, while wires 25, 26 are connected at 27 to the stick 15below its pivotal point and to the upper ends of said levers 23, 24.`Thus, a forward thrust of the-upper end of the control stick will tiltthe rear part of planes 10, 11 downwardly to cause the aircraft todescend, while a rearward thrust of said stick will effect thel oppositeresults.

The bar r17 is shown as having an upwardly projecting lever arm 2Shaving attached to its upper end wires 29, 30 reach ing in oppositedirections around pulley wheels 31, 32 to the upper ends of cross levers33, 34, fixedly connected to ailerons 8, 9'. The lower ends of saidcross levers may be interconnected by a wire 35 passing around pulleywheels 36, 37. Thus movement of the control stick 15 to the right orleft to turn bar 17 about its aXis will eEec't actuation of the aileronsthrough wires 29, 30, 35 to tilt said ailerons in opposite directionsone way or the other to control the transverse position of the aircraft.

The control of tlievertical rudder 12 may be effected by means of apedal 38 pivotally attached at 39 to a fixed portion 40 of the craft andconnecteeinen.v opposite sides 'of its pivotal axis by'wire's`41,`42, tothe opposite ends of a cross klever 43 secured to the post 13.

The wheels 6, 7 are shown as provided with brakes 44, 45, which as shownin Fig. 2

may comprise a drum 46 integral with the wheel; a brake band 47 uponsaid drum; a bracket 48 rigidly connected`v with respect to the aircraftas by being liXedly attached to the axle 5; said brake band beingattached at one end to a pin 49`integral with bracket 48, and at theother end 51 to a bell crank lever 50 pivoted at 52 to bracket 48. Thelevers 56' of the two brakes 44, 45, may be connected byv wires 53, 54,passing over pulley wheels 55, 56, to the control stick at 22. The wires53, 54 may be loose as shown, if desired, so that normal movements ofcontrol ystick 15 to actuate lthe control planes may be effected withlittle or no pull upon said wires, but any further movement of the stickwill pullupon one or both of the wires 53, `54, actuating lever 50 todraw the brake band tight upon the brake drum.

The operation is as follows:

When in flight, the aviator will steer the craft with his feet byactuation of pedal 38.

. To cause the craft to ascend or descend, he

will tilt the stick backward lor forward to tilt the horizontal rudders10, 11 upwardly or downwardly. To control the transverse position of thecraft, as in stabilizing against side air currents or in banking, thestick is tilted to one side or the other to rotate bar 17 and actuatewires 29, 30 connected to the ailerons 8 9. 'When running along theground at a slow speed, when the rudder 12 is. ineffective to steer thecraft, as for instance, when starting up for a flight, it will be seenthatactuation of pedal 38 will effect the same result on the round as inthe air inasmuch as the rear s 'd or wheel 14 will be turned. Whenlanding, steering may be done in the same manner, but may also be doneby thrusting the control stick 15 to `one side or the other to applybrake 44 or 45 to retard the wheel on the side to which` it is desiredto turn. To apply both brakes equally to bring the craft amano to aquick stop, the stick may be thrust either forward or backward to pullequally upon both wires 53 and 54, while brakino and steering maybeeffected simultaneous y by thrusting the stick backward or `forward toapply both brakes and at the Sametime moving the stick to one side orthe other to apply with greater force the brake on the side to which thecraft is tobe steered.

One advantage of steering by differentially braking the landing wheels,is, then,`

as we have seen, that the craft may also be brought to a stop morerapidly. Another advantage is that by this method steering may becommenced the moment the front wheels touch the ground and when the rearwheel 14 is still in the air. such times the craft is usually travelingat such speed that the rudder 12 is still effective for steering andboth methods may be employed. Also, after the rear wheel 14 touches theground, steering may be' effected by the turning of said wheel and bythe differential braking of the front wheels.

Thus, the action of an aeroplane upon land- -12 and skid wheel 14 mayinclude resilient sections 61, 62. The wires 53, 54 for actuatin@ thebrakes are shown as passing from the pulley wheels 5'5, 56 to the parts57, 58 of the pedal. Steering in the air will be effected by pressure onone side or the other of the pedal in the usual manner. On the groundthe same action will produce the same result. In other words, when inthe air, the aviator presses upon the part 57 of the pedal to execute aturn to the right. On the Ground, pressure upon part 57 brakes wheel 6and causes the craft to turn to the right. In order to Vapply bothbrakes at the same time, the aviator may press upon both parts 57, 58 ofthe pedal. In this instance,

he will of course press with suiiicient force Of course, at

The brake wires 53, 54 are also connected to the pedal and pass overpulley wheels 63 carried by the lever 15 pivoted at 16. Said lever maybe specially provided for braking purposes, or it may constitute thecontrol stick as in Fig. 1. Normally, actuation of pedal 38 affects onlythe steering rudder, but

when it is desired to apply the brakes, the

aviator will pull back upon the lever 15 to draw the wires 53, 54 tight.This will apply the brakes with equal pressure. By pulling the leverback and pressing on one side of the pedal, the brakes may be applieddifferentially for simultaneous braking and steering. B. pressing oneside of wthe pedal forward, an pulling back upon the lever to draw onlyone of wires 53, 54 tight but one oflthe brakes may be applied forsteering, on y.

In accordance with the provisions of the patent statutes, I have hereindescribed the principle of operation of my invention, together with theapparatus, which I now consider to represent the best embodimentthereof, but I desire to have it understood that the apparatus shown isonly illustrative and that the invention can be carried out by othermeans. Also, while it is designed to use the various features andelements in the combination and relations described, some of these maybe altered and others omitted without interfering with the more generalresults outlined, and the invention extends to such use.

Having herein described my invention, what I claim and desire to secureby Letters Patent is,

1. In combination with an aer plane having forward landing wheels an?? apivotally mounted trail wheel, of separ e brakes on said forward wheels,and a common means for differentially applying said brakes and turningsaid trail wheel whereby the aeroplane may be steered on the ground bythe cooperative action of the trail wheel and differential applicationof the brakes.

2. In combination with an aeroplane, control surfaces therefor, meansfor actuating said surfaces, Wheels for said aeroplane, brakes for saidwheels, and means connecting said brakes to said actuating means, saidbrakes bein adapted to be actuated by movement of said actuating meansbeyond a predetermined degree.

3. In combination with an aeroplane, control surfaces therefor, meansfor actuating said surfaces, wheelsfor said aeroplane, brakes for saidwheels, normally inactive control connections between said brakes andsaid actuating means, and means whereby said connections are renderedoperative after a predetermined degree of actuation of said actuatingmeans.

4. In combination with an aeroplane having a steering rudder and landingwheels, of means for actuating said rudder, brakes for said wheels,normally inactive control connections between said brakes and saidrudder-actuating means, and means whereby said connections are renderedoperative at wil 5. In combination with an aeroplane having forwardlanding wheels, a steering rudder and a trail wheel turnable with saidrudder, of separate` brakes on said forward wheels, and a common meansfor differentially applying said brakes and turning said rudder andtrail wheel whereby the airplane may be steered when landmg` 011Y theground by the cooperative action of the rudder, trail wheel anddiHerential application of the brakes..

6. In combination, an aeroplane having elevation control means,transverse positioning means, wheels, brakes for said Wheels, and asingle operating member for actuating said first two means and saidbrakes.

7. In combination, an aeroplane having elevation control rudders,transverse positioning rudders, wheels, brakes for each of said wheels,and a single operating member for differentially actuating said ruddersand said brakes.

8. In combination, an aeroplane having elevation control rudders',transverse positioning rudders, wheels, brakes for said wheels, anoperating member operable in a plurality of planes, means wherebyoperation of said member in one plane actuates said first-named rudders,and means whereby operation of said member in another plane actuatessaid second named rudders and said brakes.

9. In combination, an aeroplane having elevation control rudders,transverse positioning rudders, wheels, brakes for said wheels, anoperating member operable in a plurality of planes, means wherebyoperation of said member in one plane actuates said first-named rudders,means whereby operation of said member in, another plane actuates saidsecond-named rudders, and means whereby operation of said nmember in.said other plane beyondma predetermined degree actuates said brakes.

In testimonywhereof I yhave aiixed my signature.

LAWRENCE B. SPERRY.

